The unpredictable NFL routinely leaves those penniless who are foolish enough to think they know what's going to happen in a given week.
But the Baltimore Ravens, playing at home in an important game, have been about as close to a lead-pipe lock the league has had since John Harbaugh too over as head coach and Joe Flacco moved in at quarterback in 2008.
Even good teams throw in a clunker now and then, a bad loss in a big spot no one saw coming.
But not the Ravens. Never the Ravens.
Until Sunday, when they suffered their worst home loss ever and put up their most disappointing performance of the Harbaugh/Flacco era in a 41-7 beatdown by the New England Patriots.
"We generally have a great track record of playing in big games, especially at home," receiver Torrey Smith said.
Indeed, the Ravens had gone 39-8 at home since 2008 with seven of those losses coming by four points or fewer. And whenever they've really needed a win - like in their home finale against the New York Giants last year or in the handful of other playoff-clinchers they've faced - they've come through.
This year, too. On the verge of elimination at 4-6, they entered Sunday on a four-game winning streak and in complete control of their postseason fortunes.
Not anymore. Not after that abomination that saw them fall behind 14-0 almost immediately, trail 20-0 through three quarters and come up empty every time they had a chance to get themselves back in the game.
"It's disappointing," Flacco said. "You know, we're used to going out there and playing well when we need to, when the playoffs are on the line."
Not Sunday. Not any unit.
Forget those last two embarrassing touchdowns allowed, the fumble recovery in the end zone and the the 74-yard interception return that happened after nearly all the fans had already surrendered and were in their cars heading home. They were both the fault of backup quarterback Tyrod Taylor and were irrelevent to everyone but the fantasy owners who played the Patriots and the statisticians who needed that evidence to officially call Sunday's loss the Ravens' worst ever in Baltimore.
But the Ravens were bad from the start and the blame extends to every part of the team.
- Flacco threw two interceptions without a touchdown pass, misfiring on a couple of key fourth-down throws.
- Running backs Ray Rice and Bernard Pierce combined for 71 yards on 21 carries, a 3.4 average against the second-worst run defense in the NFL, with Rice failing on a critical fourth-and-1 from the New England 4.
- The Ravens' defense didn't get it done when it mattered, allowing touchdowns on the Patriots' second and third drives and then letting New England run all over them in the fourth quarter when it was still a two-score game.
- Even the Baltimore coaches had a rough day, as offensive coordinator Jim Caldwell made some questionable calls - an empty backfield and a fade to the tight end on third-and-one from the New England 4? - and Harbaugh made a tactical error that he couldn't explain after the game by going for a field goal with a 20-point deficit early in the fourth quarter.
"It sucked," said defensive back Corey Graham. "When it came down to it, we just didn't play well enough. It seemed like everything went their way."
Everything did go the Patriots' way. From a phantom (and important) pass interference call against Jimmy Smith in the first quarter, to the questionable spot and measurement on Rice's fourth down run. But, mostly, everything went the Patriots' way because the Ravens didn't play nearly as well as everyone expected them to.
"I don't know that we want to point to excuses or play the blame game - they beat us," defensive lineman Chris Canty said.
They surely did. At M&T Bank Stadium, which has been, statistically, the best home-field advantage in the NFL over the past decade.
And now the big Thanksgiving win over Pittsburgh, the three touchdowns in two minutes against Minnesota, the 61-yard field goal in Detroit, none of it means as much because the Ravens are in danger of missing the playoffs for the first time since 2007.
They need to win next week at Cincinnati and hope for a loss from Miami or San Diego to get in. They've been really good in such situations the past six years. At least before Sunday's disaster.
"Sometimes you make uncharacteristic mistakes and they capitalize on those things, and it just got away from us," tight end Dennis Pitta said.
"So we have to put this game behind us and get ready for Cincinnati. That's the only thing we can control."